1. Field of the Invention
The present invention relates generally to ultrasound probes and, more particularly, to removable grips for ultrasound imaging probes.
2. Related Art
The use of ultrasound for medical imaging is well-known. Since its introduction, advances in technology and clinical practice have made ultrasound a leading medical diagnostic imaging modality. Ultrasound provides high-resolution real-time imaging without the use of ionizing radiation which is required for other techniques such as X-ray imaging. In addition, modern ultrasound equipment is relatively inexpensive and portable. This cost-effectiveness and portability has resulted in the widespread application of ultrasound imaging to observe a considerable range of physical conditions and to identify many types of disorders. For example, ultrasound imaging is commonly used in such clinical applications as obstetrics and gynecology, general abdominal imaging, vascular imaging and cardiology. This latter application, which is of significance in the present application, is referred to as echocardiography.
Non-invasive echocardiography is performed generally using a transthoracic ultrasound imaging probe. Conventional transthoracic ultrasound imaging probes are generally elongated devices having an ultrasound transducer located on the distal end of the device body. Ultrasound probes are generally constructed of a hard plastic casing to facilitate cleaning. Typically, the probe is maneuvered so that the transducer is positioned adjacent to an external location on the body where acoustic imaging is facilitated by the underlying tissue. In cardiac imaging, these locations, referred to as imaging windows, are typically in the vicinity of the rib cage.
There are four primary echocardiographic imaging windows: the suprasternal, subcostal, parasternal and apical windows. The appropriateness of each imaging window depends upon the structures, functions and conditions to be diagnosed as well as the type and size of the patient. Each imaging window provides an opportunity to image a specific portion or characteristic of the cardiac structures and/or functions depending on the portion of the heart which is nearest the selected imaging window, the angle of the probe at that window, and the intervening structures which may interfere with imaging the desired cardiac structures. In addition, the utility of certain windows is limited by the size and condition of the patient. Accordingly, specific windows are used to diagnose specific imaging conditions and disorders of specific patients.
When performing transthoracic echocardiographic procedures, the patient is generally lying horizontally on his or her left side. While the patient lies still in an appropriate position, the sonographer applies the transducer to a predetermined imaging window on the patient's body. The transducer must be positioned at the correct location and in the correct orientation at the selected imaging window to successfully transmit the ultrasound signals at the proper angle so as to obtain clear and accurate cardiac images.
To place the probe in the proper position, the sonographer must maintain complete control over the probe throughout the echocardiograph procedure. This often requires the sonographer to apply a significant gripping force to the probe casing. Two techniques are commonly used. Left-handed scanning calls for holding the ultrasound probe with the left hand while manipulating the ultrasound imaging system controls with the right hand. Conversely, right-handed scanning calls for using the right hand to control the ultrasound probe while manipulating the imaging system with the left hand. Typically, a right-handed sonographer is positioned behind the horizontally-positioned patient. The sonographer must reach completely around the right side of the patient to properly position the ultrasound probe at one of the ultrasound imaging windows. The gripping force that must be applied by the sonographer to push and hold the probe in the proper location and orientation is significant in such an awkward position. In other situations, the sonographer may have to work in environments even more awkward, such as operating rooms, intensive care units, etc., as well as with patients that have difficulty remaining still, such as children and injured patients. It is not uncommon for the sonographer to repeat many procedures to ensure that the obtained images are accurate representations of the cardiac condition and not artifacts due to improper placement or orientation of the probe.
In addition, a large percentage of patients on which echocardiography is performed are obese. With these patients, the sonographer must apply a significant axial force to the probe to compress and displace layers of fat. Furthermore, the use of coupling gel to obtain a clearer image interferes with the sonographer's capability to securely hold and control the ultrasound probe when the coupling gel migrates from the transducer onto the gripping surfaces of the probe casing.
Conventional probes generally have surface features to enable the sonographer to establish the proper orientation of the probe. For example, some ultrasound probes have curves, scallops or ridges, while other probes have a localized feature such as a line, rib, flute, button or some other feature on one side of the transducer. Although such orientation-related features of conventional ultrasound probes may provide some incidental assistance to the sonographer to maintain control over the probe, these features provide insignificant and insufficient assistance, ancillary to the purpose of establishing proper orientation of the probe.
What is needed, therefore, is a means for assisting a sonographer's control of an ultrasound probe in various imaging scenarios, including different relative positions of the sonographer and the patient, varying patient conditions, and the presence or absence of coupling gel. Also, a range of gripping styles and hand sizes should be accommodated. The probe should be comfortable to hold and easily controllable with minimal gripping force to reduce fatigue and the occurrence of occupational injuries.